Previous work revealed the GRP78‐dependent cell uptake of disulfide‐linked GRP78‐targeting polyarginine peptides, (CTVALPGGYVRVC‐Rn) in the HepG2 hepatoblastoma cell line, in which cell binding and translocation activity was contingent on the length of the polyarginine sequence (Rn = 3–12) [24]. The gene discussed is HSPA5; the disease is hepatoblastoma.